About this election
The 2018 United States House of Representatives elections, held on 6 November 2018, produced a Democratic landslide widely described as a "blue wave." Democrats gained a net 41 seats to win a 235–199 majority, recapturing control of the chamber for the first time since 2010 and returning Nancy Pelosi to the Speakership. The party won the national popular vote for the House by 53.41% to 44.85% — a margin of 60,572,245 votes to 50,861,970, the largest popular-vote margin ever recorded for a party that had been in the minority.
All 435 seats were contested, as every two years, each elected by first-past-the-post in a single-member district; 218 seats are needed for a majority. Because the chamber is composed of hundreds of separately drawn districts rather than statewide contests, this page presents the national popular vote and the resulting composition of the House rather than a single regional map.
The 2018 election was the first nationwide verdict on Donald Trump's presidency, and it followed the historical pattern in which the president's party loses ground at the midterms — but on an unusually large scale. Turnout surged to about 50% of eligible voters, the highest for a midterm in a century, driven by intense engagement on both sides. Health care, particularly the defence of protections for pre-existing conditions under the Affordable Care Act, was the dominant issue in Democratic campaigns.
The wave was powered above all by suburban districts, especially those with large numbers of college-educated voters, which swung sharply against the Republicans. Democrats flipped seats across California's Orange County, the suburbs of Philadelphia, northern Virginia, the Dallas and Houston metros and the Chicago collar counties. A historically diverse and heavily female class of Democratic candidates was elected, reshaping the makeup of Congress. Republicans, by contrast, consolidated rural support and even gained two Senate seats the same night, underscoring the growing divergence between the two chambers' electoral maps.
The Democratic House majority transformed the second half of Trump's term, giving the party subpoena power and control of the legislative agenda. It led to extensive oversight of the administration and to Trump's first impeachment in December 2019. The suburban shift visible in 2018 became a defining feature of American electoral geography, central to Joe Biden's 2020 victory.
Federal Election Commission (FEC), official 2018 House general-election results — fec.gov.
Compiled and reviewed by Bartłomiej Paruzel, Election Data Analyst, from official results. See our data methodology.